diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/apic_32.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/i8259_64.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/smp.c | 158 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/smpcommon.c | 56 | ||||
| -rw-r--r-- | arch/x86/mach-voyager/voyager_smp.c | 94 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten.c | 4 | ||||
| -rw-r--r-- | arch/x86/xen/mmu.c | 2 | ||||
| -rw-r--r-- | arch/x86/xen/smp.c | 133 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 9 |
12 files changed, 103 insertions, 369 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e0edaaa6920..2f3fbebf51d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -168,6 +168,7 @@ config GENERIC_PENDING_IRQ config X86_SMP bool depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64) + select USE_GENERIC_SMP_HELPERS default y config X86_32_SMP diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c index 4b99b1bdeb6..71017f71f4b 100644 --- a/arch/x86/kernel/apic_32.c +++ b/arch/x86/kernel/apic_32.c @@ -1358,6 +1358,10 @@ void __init smp_intr_init(void) /* IPI for generic function call */ set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt); + + /* IPI for single call function */ + set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR, + call_function_single_interrupt); } #endif diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 556a8df522a..6d1fe270a96 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -711,6 +711,9 @@ END(invalidate_interrupt\num) ENTRY(call_function_interrupt) apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt END(call_function_interrupt) +ENTRY(call_function_single_interrupt) + apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt +END(call_function_single_interrupt) ENTRY(irq_move_cleanup_interrupt) apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt END(irq_move_cleanup_interrupt) diff --git a/arch/x86/kernel/i8259_64.c b/arch/x86/kernel/i8259_64.c index fa57a156850..00d2ccdc69f 100644 --- a/arch/x86/kernel/i8259_64.c +++ b/arch/x86/kernel/i8259_64.c @@ -494,6 +494,10 @@ void __init native_init_IRQ(void) /* IPI for generic function call */ set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt); + /* IPI for generic single function call */ + set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR, + call_function_single_interrupt); + /* Low priority IPI to cleanup after moving an irq */ set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt); #endif diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 0cb7aadc87c..575aa3d7248 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -121,132 +121,23 @@ static void native_smp_send_reschedule(int cpu) send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR); } -/* - * Structure and data for smp_call_function(). This is designed to minimise - * static memory requirements. It also looks cleaner. - */ -static DEFINE_SPINLOCK(call_lock); - -struct call_data_struct { - void (*func) (void *info); - void *info; - atomic_t started; - atomic_t finished; - int wait; -}; - -void lock_ipi_call_lock(void) +void native_send_call_func_single_ipi(int cpu) { - spin_lock_irq(&call_lock); -} - -void unlock_ipi_call_lock(void) -{ - spin_unlock_irq(&call_lock); -} - -static struct call_data_struct *call_data; - -static void __smp_call_function(void (*func) (void *info), void *info, - int nonatomic, int wait) -{ - struct call_data_struct data; - int cpus = num_online_cpus() - 1; - - if (!cpus) - return; - - data.func = func; - data.info = info; - atomic_set(&data.started, 0); - data.wait = wait; - if (wait) - atomic_set(&data.finished, 0); - - call_data = &data; - mb(); - - /* Send a message to all other CPUs and wait for them to respond */ - send_IPI_allbutself(CALL_FUNCTION_VECTOR); - - /* Wait for response */ - while (atomic_read(&data.started) != cpus) - cpu_relax(); - - if (wait) - while (atomic_read(&data.finished) != cpus) - cpu_relax(); + send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_SINGLE_VECTOR); } - -/** - * smp_call_function_mask(): Run a function on a set of other CPUs. - * @mask: The set of cpus to run on. Must not include the current cpu. - * @func: The function to run. This must be fast and non-blocking. - * @info: An arbitrary pointer to pass to the function. - * @wait: If true, wait (atomically) until function has completed on other CPUs. - * - * Returns 0 on success, else a negative status code. - * - * If @wait is true, then returns once @func has returned; otherwise - * it returns just before the target cpu calls @func. - * - * You must not call this function with disabled interrupts or from a - * hardware interrupt handler or from a bottom half handler. - */ -static int -native_smp_call_function_mask(cpumask_t mask, - void (*func)(void *), void *info, - int wait) +void native_send_call_func_ipi(cpumask_t mask) { - struct call_data_struct data; cpumask_t allbutself; - int cpus; - - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - - /* Holding any lock stops cpus from going down. */ - spin_lock(&call_lock); allbutself = cpu_online_map; cpu_clear(smp_processor_id(), allbutself); - cpus_and(mask, mask, allbutself); - cpus = cpus_weight(mask); - - if (!cpus) { - spin_unlock(&call_lock); - return 0; - } - - data.func = func; - data.info = info; - atomic_set(&data.started, 0); - data.wait = wait; - if (wait) - atomic_set(&data.finished, 0); - - call_data = &data; - wmb(); - - /* Send a message to other CPUs */ if (cpus_equal(mask, allbutself) && cpus_equal(cpu_online_map, cpu_callout_map)) send_IPI_allbutself(CALL_FUNCTION_VECTOR); else send_IPI_mask(mask, CALL_FUNCTION_VECTOR); - - /* Wait for response */ - while (atomic_read(&data.started) != cpus) - cpu_relax(); - - if (wait) - while (atomic_read(&data.finished) != cpus) - cpu_relax(); - spin_unlock(&call_lock); - - return 0; } static void stop_this_cpu(void *dummy) @@ -268,18 +159,13 @@ static void stop_this_cpu(void *dummy) static void native_smp_send_stop(void) { - int nolock; unsigned long flags; if (reboot_force) return; - /* Don't deadlock on the call lock in panic */ - nolock = !spin_trylock(&call_lock); + smp_call_function(stop_this_cpu, NULL, 0, 0); local_irq_save(flags); - __smp_call_function(stop_this_cpu, NULL, 0, 0); - if (!nolock) - spin_unlock(&call_lock); disable_local_APIC(); local_irq_restore(flags); } @@ -301,33 +187,28 @@ void smp_reschedule_interrupt(struct pt_regs *regs) void smp_call_function_interrupt(struct pt_regs *regs) { - void (*func) (void *info) = call_data->func; - void *info = call_data->info; - int wait = call_data->wait; - ack_APIC_irq(); - /* - * Notify initiating CPU that I've grabbed the data and am - * about to execute the function - */ - mb(); - atomic_inc(&call_data->started); - /* - * At this point the info structure may be out of scope unless wait==1 - */ irq_enter(); - (*func)(info); + generic_smp_call_function_interrupt(); #ifdef CONFIG_X86_32 __get_cpu_var(irq_stat).irq_call_count++; #else add_pda(irq_call_count, 1); #endif irq_exit(); +} - if (wait) { - mb(); - atomic_inc(&call_data->finished); - } +void smp_call_function_single_interrupt(void) +{ + ack_APIC_irq(); + irq_enter(); + generic_smp_call_function_single_interrupt(); +#ifdef CONFIG_X86_32 + __get_cpu_var(irq_stat).irq_call_count++; +#else + add_pda(irq_call_count, 1); +#endif + irq_exit(); } struct smp_ops smp_ops = { @@ -338,7 +219,8 @@ struct smp_ops smp_ops = { .smp_send_stop = native_smp_send_stop, .smp_send_reschedule = native_smp_send_reschedule, - .smp_call_function_mask = native_smp_call_function_mask, + + .send_call_func_ipi = native_send_call_func_ipi, + .send_call_func_single_ipi = native_send_call_func_single_ipi, }; EXPORT_SYMBOL_GPL(smp_ops); - diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 56078d61c79..89647898f54 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -345,7 +345,7 @@ static void __cpuinit start_secondary(void *unused) * lock helps us to not include this cpu in a currently in progress * smp_call_function(). */ - lock_ipi_call_lock(); + ipi_call_lock_irq(); #ifdef CONFIG_X86_64 spin_lock(&vector_lock); @@ -357,7 +357,7 @@ static void __cpuinit start_secondary(void *unused) spin_unlock(&vector_lock); #endif cpu_set(smp_processor_id(), cpu_online_map); - unlock_ipi_call_lock(); + ipi_call_unlock_irq(); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; setup_secondary_clock(); diff --git a/arch/x86/kernel/smpcommon.c b/arch/x86/kernel/smpcommon.c index 3449064d141..99941b37eca 100644 --- a/arch/x86/kernel/smpcommon.c +++ b/arch/x86/kernel/smpcommon.c @@ -25,59 +25,3 @@ __cpuinit void init_gdt(int cpu) per_cpu(cpu_number, cpu) = cpu; } #endif - -/** - * smp_call_function(): Run a function on all other CPUs. - * @func: The function to run. This must be fast and non-blocking. - * @info: An arbitrary pointer to pass to the function. - * @nonatomic: Unused. - * @wait: If true, wait (atomically) until function has completed on other CPUs. - * - * Returns 0 on success, else a negative status code. - * - * If @wait is true, then returns once @func has returned; otherwise - * it returns just before the target cpu calls @func. - * - * You must not call this function with disabled interrupts or from a - * hardware interrupt handler or from a bottom half handler. - */ -int smp_call_function(void (*func) (void *info), void *info, int nonatomic, - int wait) -{ - return smp_call_function_mask(cpu_online_map, func, info, wait); -} -EXPORT_SYMBOL(smp_call_function); - -/** - * smp_call_function_single - Run a function on a specific CPU - * @cpu: The target CPU. Cannot be the calling CPU. - * @func: The function to run. This must be fast and non-blocking. - * @info: An arbitrary pointer to pass to the function. - * @nonatomic: Unused. - * @wait: If true, wait until function has completed on other CPUs. - * - * Returns 0 on success, else a negative status code. - * - * If @wait is true, then returns once @func has returned; otherwise - * it returns just before the target cpu calls @func. - */ -int smp_call_function_single(int cpu, void (*func) (void *info), void *info, - int nonatomic, int wait) -{ - /* prevent preemption and reschedule on another processor */ - int ret; - int me = get_cpu(); - if (cpu == me) { - local_irq_disable(); - func(info); - local_irq_enable(); - put_cpu(); - return 0; - } - - ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait); - - put_cpu(); - return ret; -} -EXPORT_SYMBOL(smp_call_function_single); diff --git a/arch/x86/mach-voyager/voyager_smp.c b/arch/x86/mach-voyager/voyager_smp.c index 8acbf0cdf1a..cb34407a993 100644 --- a/arch/x86/mach-voyager/voyager_smp.c +++ b/arch/x86/mach-voyager/voyager_smp.c @@ -955,94 +955,24 @@ static void smp_stop_cpu_function(void *dummy) halt(); } -static DEFINE_SPINLOCK(call_lock); - -struct call_data_struct { - void (*func) (void *info); - void *info; - volatile unsigned long started; - volatile unsigned long finished; - int wait; -}; - -static struct call_data_struct *call_data; - /* execute a thread on a new CPU. The function to be called must be * previously set up. This is used to schedule a function for * execution on all CPUs - set up the function then broadcast a * function_interrupt CPI to come here on each CPU */ static void smp_call_function_interrupt(void) { - void (*func) (void *info) = call_data->func; - void *info = call_data->info; - /* must take copy of wait because call_data may be replaced - * unless the function is waiting for us to finish */ - int wait = call_data->wait; - __u8 cpu = smp_processor_id(); - - /* - * Notify initiating CPU that I've grabbed the data and am - * about to execute the function - */ - mb(); - if (!test_and_clear_bit(cpu, &call_data->started)) { - /* If the bit wasn't set, this could be a replay */ - printk(KERN_WARNING "VOYAGER SMP: CPU %d received call funtion" - " with no call pending\n", cpu); - return; - } - /* - * At this point the info structure may be out of scope unless wait==1 - */ irq_enter(); - (*func) (info); + generic_smp_call_function_interrupt(); __get_cpu_var(irq_stat).irq_call_count++; irq_exit(); - if (wait) { - mb(); - clear_bit(cpu, &call_data->finished); - } } -static int -voyager_smp_call_function_mask(cpumask_t cpumask, - void (*func) (void *info), void *info, int wait) +static void smp_call_function_single_interrupt(void) { - struct call_data_struct data; - u32 mask = cpus_addr(cpumask)[0]; - - mask &= ~(1 << smp_processor_id()); - - if (!mask) - return 0; - - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - - data.func = func; - data.info = info; - data.started = mask; - data.wait = wait; - if (wait) - data.finished = mask; - - spin_lock(&call_lock); - call_data = &data; - wmb(); - /* Send a message to all other CPUs and wait for them to respond */ - send_CPI(mask, VIC_CALL_FUNCTION_CPI); - - /* Wait for response */ - while (data.started) - barrier(); - - if (wait) - while (data.finished) - barrier(); - - spin_unlock(&call_lock); - - return 0; + irq_enter(); + generic_smp_call_function_single_interrupt(); + __get_cpu_var(irq_stat).irq_call_count++; + irq_exit(); } /* Sorry about the name. In an APIC based system, the APICs @@ -1099,6 +1029,12 @@ void smp_qic_call_function_interrupt(struct pt_regs *regs) smp_call_function_interrupt(); } +void smp_qic_call_function_single_interrupt(struct pt_regs *regs) +{ + ack_QIC_CPI(QIC_CALL_FUNCTION_SINGLE_CPI); + smp_call_function_single_interrupt(); +} + void smp_vic_cpi_interrupt(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); @@ -1119,6 +1055,8 @@ void smp_vic_cpi_interrupt(struct pt_regs *regs) smp_enable_irq_interrupt(); if (test_and_clear_bit(VIC_CALL_FUNCTION_CPI, &vic_cpi_mailbox[cpu])) smp_call_function_interrupt(); + if (test_and_clear_bit(VIC_CALL_FUNCTION_SINGLE_CPI, &vic_cpi_mailbox[cpu])) + smp_call_function_single_interrupt(); set_irq_regs(old_regs); } @@ -1862,5 +1800,7 @@ struct smp_ops smp_ops = { .smp_send_stop = voyager_smp_send_stop, .smp_send_reschedule = voyager_smp_send_reschedule, - .smp_call_function_mask = voyager_smp_call_function_mask, + + .send_call_func_ipi = native_send_call_func_ipi, + .send_call_func_single_ipi = native_send_call_func_single_ipi, }; diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index f09c1c69c37..8e317782fe3 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1108,7 +1108,9 @@ static const struct smp_ops xen_smp_ops __initdata = { .smp_send_stop = xen_smp_send_stop, .smp_send_reschedule = xen_smp_send_reschedule, - .smp_call_function_mask = xen_smp_call_function_mask, + + .send_call_func_ipi = xen_smp_send_call_function_ipi, + .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, }; #endif /* CONFIG_SMP */ diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index df40bf74ea7..5c01590380b 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -558,7 +558,7 @@ static void drop_mm_ref(struct mm_struct *mm) } if (!cpus_empty(mask)) - xen_smp_call_function_mask(mask, drop_other_mm_ref, mm, 1); + smp_call_function_mask(mask, drop_other_mm_ref, mm, 1); } #else static void drop_mm_ref(struct mm_struct *mm) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 94e69000f98..b3786e749b8 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -36,27 +36,14 @@ #include "mmu.h" static cpumask_t xen_cpu_initialized_map; -static DEFINE_PER_CPU(int, resched_irq) = -1; -static DEFINE_PER_CPU(int, callfunc_irq) = -1; -static DEFINE_PER_CPU(int, debug_irq) = -1; - -/* - * Structure and data for smp_call_function(). This is designed to minimise - * static memory requirements. It also looks cleaner. - */ -static DEFINE_SPINLOCK(call_lock); -struct call_data_struct { - void (*func) (void *info); - void *info; - atomic_t started; - atomic_t finished; - int wait; -}; +static DEFINE_PER_CPU(int, resched_irq); +static DEFINE_PER_CPU(int, callfunc_irq); +static DEFINE_PER_CPU(int, callfuncsingle_irq); +static DEFINE_PER_CPU(int, debug_irq) = -1; static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id); - -static struct call_data_struct *call_data; +static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id); /* * Reschedule call back. Nothing to do, @@ -122,6 +109,17 @@ static int xen_smp_intr_init(unsigned int cpu) goto fail; per_cpu(debug_irq, cpu) = rc; + callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); + rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, + cpu, + xen_call_function_single_interrupt, + IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, + callfunc_name, + NULL); + if (rc < 0) + goto fail; + per_cpu(callfuncsingle_irq, cpu) = rc; + return 0; fail: @@ -131,6 +129,9 @@ static int xen_smp_intr_init(unsigned int cpu) unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); if (per_cpu(debug_irq, cpu) >= 0) unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); + if (per_cpu(callfuncsingle_irq, cpu) >= 0) + unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); + return rc; } @@ -338,7 +339,6 @@ void xen_smp_send_reschedule(int cpu) xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); } - static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector) { unsigned cpu; @@ -349,83 +349,42 @@ static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector) xen_send_IPI_one(cpu, vector); } +void xen_smp_send_call_function_ipi(cpumask_t mask) +{ + int cpu; + + xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); + + /* Make sure other vcpus get a chance to run if they need to. */ + for_each_cpu_mask(cpu, mask) { + if (xen_vcpu_stolen(cpu)) { + HYPERVISOR_sched_op(SCHEDOP_yield, 0); + break; + } + } +} + +void xen_smp_send_call_function_single_ipi(int cpu) +{ + xen_send_IPI_mask(cpumask_of_cpu(cpu), XEN_CALL_FUNCTION_SINGLE_VECTOR); +} + static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) { - void (*func) (void *info) = call_data->func; - void *info = call_data->info; - int wait = call_data->wait; - - /* - * Notify initiating CPU that I've grabbed the data and am - * about to execute the function - */ - mb(); - atomic_inc(&call_data->started); - /* - * At this point the info structure may be out of scope unless wait==1 - */ irq_enter(); - (*func)(info); + generic_smp_call_function_interrupt(); __get_cpu_var(irq_stat).irq_call_count++; irq_exit(); - if (wait) { - mb(); /* commit everything before setting finished */ - atomic_inc(&call_data->finished); - } - return IRQ_HANDLED; } -int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *), - void *info, int wait) +static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) { - struct call_data_struct data; - int cpus, cpu; - bool yield; - - /* Holding any lock stops cpus from going down. */ - spin_lock(&call_lock); - - cpu_clear(smp_processor_id(), mask); - - cpus = cpus_weight(mask); - if (!cpus) { - spin_unlock(&call_lock); - return 0; - } - - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - - data.func = func; - data.info = info; - atomic_set(&data.started, 0); - data.wait = wait; - if (wait) - atomic_set(&data.finished, 0); - - call_data = &data; - mb(); /* write everything before IPI */ - - /* Send a message to other CPUs and wait for them to respond */ - xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); - - /* Make sure other vcpus get a chance to run if they need to. */ - yield = false; - for_each_cpu_mask(cpu, mask) - if (xen_vcpu_stolen(cpu)) - yield = true; - - if (yield) - HYPERVISOR_sched_op(SCHEDOP_yield, 0); - - /* Wait for response */ - while (atomic_read(&data.started) != cpus || - (wait && atomic_read(&data.finished) != cpus)) - cpu_relax(); - - spin_unlock(&call_lock); + irq_enter(); + generic_smp_call_function_single_interrupt(); + __get_cpu_var(irq_stat).irq_call_count++; + irq_exit(); - return 0; + return IRQ_HANDLED; } diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index f1063ae0803..a636ab5e134 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -46,13 +46,8 @@ void xen_smp_cpus_done(unsigned int max_cpus); void xen_smp_send_stop(void); void xen_smp_send_reschedule(int cpu); -int xen_smp_call_function (void (*func) (void *info), void *info, int nonatomic, - int wait); -int xen_smp_call_function_single(int cpu, void (*func) (void *info), void *info, - int nonatomic, int wait); - -int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *), - void *info, int wait); +void xen_smp_send_call_function_ipi(cpumask_t mask); +void xen_smp_send_call_function_single_ipi(int cpu); /* Declare an asm function, along with symbols needed to make it |